- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[Advances in Heterocyclic Chemistry] || Recent developments in the synthesis of the BODIPY dyes
摘要： The BODIPYs are a very widely used class of fluorescent dyes, based around a heterocyclic organic framework, which have found applications across a broad range of research areas and real-world applications. Their popularity and utility derive from a winning combination of easily controllable photophysical properties and synthetic accessibility. Since their inception in 1968, considerable research has been directed toward the understanding, improvement, and development of flexible synthetic methodologies toward this privileged class of organic molecules. In this review we seek both to present an overview of commonly used synthetic methods and to highlight recent developments in the synthesis and modification of BODIPY dyes.
关键词： Dipyrromethene,Boron-chelated,Organic fluorophores,dipyrromethene,BODIPY,Synthesis,Dipyrromethane,4,40-Difluoro-4-bora-3a,4a-diaza-s-indacene
更新于2025-09-19 17:15:36
-
Spectroscopic properties of Dy3+- and Dy3+, B3+- doped SrAl2O4
摘要： The dysprosium and boron effect on the emission properties of europium-doped SrAl2O4 samples has recently attracted considerable attention due to their high brightness and long afterglow. Here, the influence of both cations, Dy3+ and B3+, on the spectroscopic properties of the europium free samples SrAl2O4:Dy3+ and SrAl2O4:Dy3+, B3+ has been investigated in order to get more insights concerning the mechanism by which they enhance the afterglow. Unique features have been observed in their excitation and emission spectra that show on one hand the lattice defects induced by the replacement of Sr2+ by Dy3+ and proves the existence of different crystallography sites for the Dy3+ ions and on the other hand, the local distortion of the energy levels of Dy3+ ions in the presence of B3+.
关键词： Doping,Persistent phosphors,Dysprosium,SrAl2O4,Boron,Phosphorescence
更新于2025-09-19 17:15:36
-
Boron(III) Carbazosubphthalocyanines: Core-Expanded Antiaromatic Boron(III) Subphthalocyanine Analogues
摘要： Condensation of 1,8-diamino-3,6-dichlorocarbazole with a series of disubstituted 1,3-diiminoisoindolines followed by treatment with BF3·OEt2 led to the formation of the corresponding core-expanded boron(III) subphthalocyanine analogues. These air-stable π-conjugated boron(III) carbazosubphthalocyanines possess two boron-containing seven-membered ring units and a 16 π-electron skeleton, which represent the first examples of antiaromatic boron(III) subphthalocyanine analogues as supported by spectroscopic and theoretical studies. The molecular structure of one of these compounds was also unambiguously determined by single-crystal X-ray diffraction analysis. In contrast to typical boron(III) subphthalocyanines which adopt a cone-shaped structure, the π skeleton of this compound is almost planar.
关键词： magnetic circular dichroism,boron,subphthalocyanines,Antiaromaticity,ring expansion
更新于2025-09-19 17:15:36
-
Fabrication of nanoheterostructures of boron doped ZnO-MoS2 with enhanced photostability and photocatalytic activity for environmental remediation applications
摘要： In this work, we have developed two dimensional (2D) nanosheets-nanoparticles (0D) nanoheterostructures of boron-doped ZnO nanoparticles loaded over MoS2 nanosheets with enhanced photocatalytic activity for pollutant removal. A series of nanoheterostructures with varying amount of MoS2 nanosheets were prepared using facile hydrothermal method and characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques to confirm there successful synthesis. The optimized nanoheterostructure photocatalyst with 1 wt% of MoS2 nanosheets (BZM1) exhibits superior photocatalytic activity for pollutant removal under visible light illumination. The superior photocatalytic activity of BZM1 nanoheterostructure has been supported by photoluminescence (PL) studies which show the remarkably decreased PL intensity signifying the low recombination rate of photogenerated charge carriers. In addition, the formation of 0D-2D heterojunction plays a significant role in enhancing the photocatalytic activity by accelerated photogenerated charge carriers separation in space and ultimately improved photocatalytic activity. Furthermore, the plausible photocatalytic mechanism has been discussed in detail on the basis of active species trapping experiment which validate the significant role of holes and hydroxyl radicals in degradation process. Overall, this work paves way for the facile fabrication of 0D-2D nanoheterostructures for diverse applications.
关键词： Boron doped ZnO,charge transfer,B-ZnO-MoS2 nanoheterostructures,environmental remediation,photocatalysis
更新于2025-09-19 17:15:36
-
Anisotropic Flow Control and Gate Modulation of Hybrid Phonon-Polaritons
摘要： Light-matter interaction in two-dimensional photonic materials allows for confinement and manipulation of free-space radiation in sub-wavelength scales. Most notably, the van der Waals heterostructure comprising graphene (G) and hexagonal Boron Nitride (hBN) provides for gate-tunable hybrid hyperbolic plasmon phonon-polaritons (HP3). Here, we present anisotropic flow control and gate voltage modulation of HP3 modes in G-hBN lying on air-Au microstructured substrate. Using broadband infrared synchrotron radiation coupled to a scattering-type near-field optical microscope, we launch HP3 waves in both hBN Reststrahlen bands and observe directional propagation across in-plane heterointerfaces created at the air-Au junction. HP3 hybridization is modulated by varying the gate voltage between graphene and Au. In this case, we induce modifications to the coupling of continuum graphene plasmons with the discrete hBN hyperbolic phonon polaritons, which is interpreted as an extended Fano model. This is the first demonstration of control of polariton propagation, including a theoretical approach for a break of the reflection/transmission symmetry for HP3 modes. Our findings augment the degree of control of polaritons in G-hBN and related hyperbolic metamaterial nanostructures bringing novel insights to on-chip nano-optics communication and computing.
关键词： polaritonics,nano-photonics,graphene/boron nitride,near-field optics,hybrid polaritons,synchrotron infrared
更新于2025-09-19 17:15:36
-
Effect of Net Charge on the Relative Stability of 2D Boron Allotropes
摘要： We study the effect of electron doping on the bonding character and stability of two-dimensional (2D) structures of elemental boron, called borophene, which is known to form many stable allotropes. Our ab initio calculations for the neutral system reveal previously unknown stable 2D ε-B and ω-B structures. We find that the chemical bonding characteristic in this and other boron structures is strongly affected by extra charge. Beyond a critical degree of electron doping, the most stable allotrope changes from ε-B to a buckled honeycomb structure. Additional electron doping, mimicking a transformation of boron to carbon, causes a gradual decrease in the degree of buckling of the honeycomb lattice that can be interpreted as piezoelectric response. Net electron doping can be achieved by placing borophene in direct contact with layered electrides such as Ca2N. We find that electron doping can be doubled by changing from the B/Ca2N bilayer to the Ca2N/B/Ca2N sandwich geometry.
关键词： doping,boron,2D,ab initio calculation,structural stability,electronic structure
更新于2025-09-19 17:15:36
-
A novel hydrogenated boron–carbon monolayer with high stability and promising carrier mobility
摘要： Although immense research on the extension of the two-dimensional (2D) material family has been carried out, 2D materials with a satisfactory band gap, high carrier mobility, and outstanding thermodynamic stability under ambient conditions are still limited. In this work, using first principles calculations, we proposed new 2D ternary materials consisting of C, B, and H atoms, namely hexagonal-BCH (h-BCH) and tetragonal-BCH (t-BCH). Both phonon calculations and ab initio molecular dynamics simulations show that these proposed sheets are thermodynamically stable phases. The electronic structure calculations indicate that h-BCH and t-BCH sheets are semiconductors with a band gap of 2.66 and 2.22 eV, respectively. Remarkably, the h-BCH (t-BCH) sheet exhibits electron mobility as high as 7.41 × 10^3 (1.09 × 10^3) cm^2 V^{-1} s^{-1}, which is higher than that of the MoS2 monolayer, though the hole mobility is about one (two) order of magnitude lower. Equally important is the fact that the position of both the conduction and valence band edges of the h-BCH sheet matches well with the chemical reaction potential of H2/H+ and O2/H2O, giving a 2D photocatalyst as a potential candidate for overall visible-light-driven water splitting. Therefore, the designed h-BCH and t-BCH monolayers have promising applications in future electronics and photocatalysts.
关键词： 2D materials,boron-carbon-hydrogen,photocatalysis,first principles calculations,carrier mobility
更新于2025-09-19 17:15:36
-
[IEEE 2018 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Hong Kong (2018.11.5-2018.11.9)] 2018 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Evaluating Two-Photon Absorption Effects on Pulsed High-Power Laser Operation
摘要： Pure gallium and pure boron (PureGaB) Ge-on-Si photodiodes were fabricated in a CMOS compatible process and operated in linear and avalanche mode. Three different pixel geometries with very different area-to-perimeter ratios were investigated in linear arrays of 300 pixels with each a size of 26 × 26 μm2. The processing of anode contacts at the anode perimeters leaving oxide covered PureGaB-only light-entrance windows, created perimeter defects that increased the vertical Ge volume but did not deteriorate the diode ideality. The dark current at 1 V reverse bias was below 35 μA/cm2 at room temperature and below the measurement limit of 2.5 × 10?2 μA/cm2 at 77 K. Spread in dark current levels and optical gain, that reached the range of 106 at 77 K, was lowest for the devices with largest perimeter. All device types were reliably operational in a wide temperature range from 77 K to room temperature. The spectral sensitivity of the detectors extended from visible to the telecom band with responsivities of 0.15 and 0.135 A/W at 850 and 940 nm, respectively.
关键词： Avalanche photodiode (APD),near-infrared photodiode,Ge-on-Si,pure gallium and pure boron (PureGaB)
更新于2025-09-19 17:13:59
-
Improved breakdown strength of Poly(vinylidene Fluoride)-based composites by using all ball-milled hexagonal boron nitride sheets without centrifugation
摘要： Hexagonal boron nitride (h-BN) is an ideal candidate to endow ferroelectric polymers with high energy density ((cid:1)(cid:2)) due to its intrinsic high breakdown strength ((cid:3)(cid:4)) of 800 kV/mm. Generally, it is believed that only boron nitride nanosheets (BNNSs) could remarkably improve (cid:3)(cid:4) of composite. Nevertheless, low-yield and time-consuming preparation procedures of BNNSs greatly limits the application of h-BN. To overcome this challenge, in this study, all ball-milled h-BN (B-BN) sheets were entirely used to enhance (cid:3)(cid:4) of poly(vinylidene fluoride) (PVDF) without any further centrifugation. (cid:3)(cid:4) of composites increased as ball-milling time increases at filler content of 8 wt%. Remarkably, PVDF with h-BN ball-milled for 16 h (B16-BN) possesses an impressive (cid:3)(cid:4) value of 506.8 kV/mm, which is 2.86 times that of neat PVDF (272.4 kV/mm) and even 1.33 times higher than that of PVDF/h-BN composites (380.6 kV/mm). (cid:3)(cid:4) of PVDF/B16-BN composites is close to that of PVDF/OH-BNNSs composites at same filler content, suggesting that the centrifugation is not a necessary procedure. Besides, improved dielectric loss, calculated (cid:1)(cid:2), mechanical properties and in-plane thermal conductivity can also be achieved for PVDF/B16-BN composites. These improved properties of PVDF/B16-BN composites indicate that the employment of B16-BN can avoid the weakness of low-yield and time-consuming preparation procedure of BNNSs and broaden its applications in the field of energy storage. Finally, the improved dispersion of OH-BN as well as synergy effect (f) on (cid:3)(cid:4) between OH-BN and OH-BNNSs were discussed to better understand these improved properties of PVDF/B16-BN composites.
关键词： Breakdown strength,No centrifugation,Synergy effect,Hexagonal boron nitride
更新于2025-09-19 17:13:59
-
Single-Walled boron nitride nanotubes interaction with nickel, titanium, palladium, and gold metal atoms- A first-principles study
摘要： Ab initio calculations based on density functional theory was carried out to study the electronic properties of (3,3), (4,2), (5,2) and (6,0) boron nitride nanotubes when interacting with nickel, titanium, palladium and gold metal atoms. These interactions occurred via adsorption, intercalation, nitrogen substitutional doping and boron substitutional doping. The wide band gaps intrinsic to the pristine boron nitride nanotubes were successfully tuned upon interaction with the metal atoms irrespective of the type of interactions. However, for most of the interactions that occurred via intercalation and nitrogen substitutional doping, the boron nitride nanotube was found to possess semi-metallic properties. More states were added in the density of states upon interaction in which the d orbital of the transition metal atoms was found to be the major contributor to the increase in density of states.
关键词： Transition metals,Fermi energy,Density functional theory,Band gap,Boron nitride nanotubes
更新于2025-09-19 17:13:59